In the coastal south of Bangladesh, rice paddies that farmers could once harvest three times a year lie barren. Sea-level rise brings saltwater to the soil, ruining the staple crop. It's one of many impacts, and inequities, of climate change. Despite producing less than one percent of global carbon emissions, Bangladesh is suffering more than most countries. Rising seas, heat waves, flooding, and cyclones threaten 90 million people.
A platform being developed in a collaboration between MIT and BRAC, a Bangladesh-based global development organisation, aims to inform and empower climate-threatened communities to proactively adapt to a changing future. Selected as one of five MIT Climate Grand Challenges flagship projects, the Climate Resilience Early Warning System (CREWSnet) will forecast the local impacts of climate change on people's lives, homes, and livelihoods. These forecasts will guide BRAC's development of climate-resiliency programs to help residents prepare for and adapt to life-altering conditions.
"The communities that CREWSnet will focus on have done little to contribute to the problem of climate change in the first place. However, because of socioeconomic situations, they may be among the most vulnerable. We hope that by providing state-of-the-art projections and sharing them broadly with communities, and working through partners like BRAC, we can help improve the capacity of local communities to adapt to climate change, significantly," says Elfatih Eltahir, the H.M. King Bhumibol Professor in the Department of Civil and Environmental Engineering.
Predicting local risks
CREWSnet's forecasts rely upon a sophisticated model, developed in Eltahir's research group over the past 25 years, called the MIT Regional Climate Model. This model zooms in on climate processes at local scales, at a resolution as granular as 6 miles. In Bangladesh’s population-dense cities, a 6-mile area could encompass tens, or even hundreds, of thousands of people. The model takes into account the details of a region’s topography, land use, and coastline to predict changes in local conditions.
When applying this model to Bangladesh, researchers found that heatwaves will get more severe and more frequent over the next 30 years. In particular, wet-bulb temperatures, which indicate the ability of humans to cool down by sweating, will rise to dangerous levels rarely observed today, particularly in western, inland cities.
Such hot spots exacerbate other challenges predicted to worsen near Bangladesh's coast. Rising sea levels and powerful cyclones are eroding and flooding coastal communities, causing saltwater to surge into land and freshwater. This salinity intrusion is detrimental to human health, ruins drinking water supplies, and harms crops, livestock, and aquatic life that farmers and fishermen depend on for food and income.
CREWSnet will fuse climate science with forecasting tools that predict the social and economic impacts on villages and cities. These forecasts – such as how often a crop season may fail, or how far floodwaters will reach – can steer decision-making.
"What people need to know, whether they're a governor or head of a household, is 'What is going to happen in my area, and what decisions should I make for the people I'm responsible for?' Our role is to integrate this science and technology together into a decision support system," says Aldridge.
"We know that making decisions based on climate change requires a deep level of trust. That's why having a powerful partner like BRAC is so important," he says.
Testing interventions
Established 50 years ago, just after Bangladesh's independence, BRAC works in every district of the nation to provide social services that help people rise from extreme poverty. Today, it is one of the world's largest nongovernmental organisations, serving 110 million people across 11 countries in Asia and Africa, but its success is cultivated locally.
"BRAC is thrilled to partner with leading researchers at MIT to increase climate resilience in Bangladesh and provide a model that can be scaled around the globe,” says Donella Rapier, President and CEO of BRAC USA.
“Locally led climate adaptation solutions that are developed in partnership with communities are urgently needed, particularly in the most vulnerable regions that are on the frontlines of climate change.”
CREWSnet will help BRAC identify communities most vulnerable to forecasted impacts. In these areas, they will share knowledge and innovate or bolster programs to improve households' capacity to adapt.
Many climate initiatives are already underway. One program equips homes to filter and store rainwater, as salinity intrusion makes safe drinking water hard to access. Another program is building resilient housing, able to withstand 120-mile-per-hour winds, that can double as local shelters during cyclones and flooding. Other services are helping farmers switch to different livestock or crops better suited for wetter or saltier conditions (e.g., ducks instead of chickens, or salt-tolerant rice), and providing interest-free loans to enable this change.
But adapting in place will not always be possible, for example, in areas predicted to be submerged or unbearably hot by midcentury. “Bangladesh is working on identifying and developing climate-resilient cities and towns across the country, as closer-by alternative destinations as compared to moving to Dhaka, the overcrowded capital of Bangladesh,” says Campbell.
“CREWSnet can help identify regions better suited for migration, and climate-resilient adaptation strategies for those regions.”
At the same time, BRAC's Climate Bridge Fund is helping to prepare cities for climate-induced migration, building up infrastructure and financial services for people who have been displaced.
The team aspires to bring CREWSnet to other nations disproportionately impacted by climate change. "Our vision is to have this be a globally extensible capability," says Campbell.